The blade tip speed of a backward bladed centrifugal fan running at 300 rpm delivers 120 m³/s of air. If the tip speed of the blade is 47.12 m/s and width of the fan is 1.3 m then the radial velocity of air at the periphery of the impeller in m/s is

The liquid employed in aneroid barometer.

The mechanical mixture of gases existing in a mine given off after explosion called

A Drager Gas Mask does not filter

The resistances of two splits A and Bare 0.35 Ns²m^-8 and 0.05 Ns²m^-8 respectively. The combined resistance of the shafts and trunk airways is 0.4 Ns²m^-8. A booster fan is planned to be installed in split A to increase the quantity flowing through it. Assuming that the surface fan continues to operate at a constant pressure of 1000 Pa, the critical pressure of the booster fan in Pa is